What is the treatment for Vitamin B12 (Cobalamin) deficiency?

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From the Guidelines

Vitamin B12 deficiency should be treated immediately with hydroxocobalamin 1 mg intramuscularly, with the treatment regimen varying depending on the presence of neurological involvement.

Treatment Regimens

  • For people with neurological involvement, hydroxocobalamin 1 mg intramuscularly should be administered on alternate days until there is no further improvement, then hydroxocobalamin 1 mg intramuscularly every 2 months 1.
  • For people with no neurological involvement, hydroxocobalamin 1 mg intramuscularly should be administered three times a week for 2 weeks, followed by maintenance treatment with 1 mg intramuscularly every 2–3 months for life 1.

Oral Treatment

Oral vitamin B12 treatment may be considered, with a preferred dose of 1 mg daily, as it is likely to be at least as effective as lower doses and more convenient for patients 1.

Special Considerations

  • Patients with ileal involvement and/or resection and/or clinical deficiency features should be screened yearly for B12 deficiency, and those with clinical deficiency should receive 1000 mg of vitamin B12 by intramuscular injection every other day for a week and then every month for life 1.
  • Folic acid deficiency should be treated with oral folic acid 5 mg daily for a minimum of 4 months, but only after excluding vitamin B12 deficiency 1.

From the Research

Treatment Options for Vitamin B12 Deficiency

The treatment for Vitamin B12 (Cobalamin) deficiency can vary depending on the cause and severity of the deficiency. The following are some of the treatment options:

  • Intramuscular injections: This has been the mainstay of treatment for Vitamin B12 deficiency, especially for patients with severe deficiency or those who have difficulty absorbing the vitamin from food 2, 3.
  • Oral replacement therapy: This can be effective in many cases, especially for patients with mild deficiency or those who have difficulty with intramuscular injections 2, 3.
  • High-dose oral B12: This may be considered for long-term treatment, especially for patients who have difficulty with intramuscular injections or who prefer oral therapy 3, 4.
  • Parenteral supplementation: This is preferred for patients with B12 malabsorption, as oral supplementation may be insufficient 3.

Factors Influencing Treatment

The treatment for Vitamin B12 deficiency depends on several factors, including:

  • Cause of the deficiency: The treatment may vary depending on whether the deficiency is due to inadequate intake, malabsorption, or other factors 3, 4.
  • Severity of the deficiency: Patients with severe deficiency may require more aggressive treatment, such as intramuscular injections 3, 4.
  • Patient lifestyle and medical history: The treatment may need to be tailored to the individual patient's needs and medical history 4.

Monitoring and Adjusting Treatment

The treatment for Vitamin B12 deficiency may need to be monitored and adjusted over time. This can include:

  • Measuring biomarkers such as serum B12, methylmalonic acid, and homocysteine to assess the effectiveness of treatment 3, 4.
  • Adjusting the dose or frequency of treatment based on the patient's response to therapy 3, 4.
  • Considering individualized treatment regimens for patients who require more frequent administration of Vitamin B12 3.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Vitamin B12 deficiency - A 21st century perspective .

Clinical medicine (London, England), 2015

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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